Remington 12 troubleshooting

[jcj54]

I have a Remington 12 sn377505 which is mated to a lower/buttstock sn637074.
The action slide/bolt cycles fine when disassembled, but binds badly when it is assembled.
I think it has something to do with the carrier , but am not sure.
Any suggestions would be appreciated.

[Eddie Southgate]

I have no expertise in any area pertaining to working on any Remington pump but I have read a lot about them . If the model 12 is anything like the older model 14, 14 1/2 , 25's , everything inside them was hand fitted to one specific rifle and almost never interchange directly into another rifle of the same type . That's even if made the same day by the same individual . My guess is the fact that you have two different serial numbers on the two assembly's is the sum total of your problem . Nothing is fitted to anything . I could be wrong but I doubt it . It will likely take a real gunsmith to put the two ends together and make it work properly . Real Gunsmiths are as rare as hens teeth now days . I have a model 25 with what I think is probably a minor issue but I cant see what's causing the problem and nobody works on them anymore . I wish you better luck .